JustCoding News: Inpatient, May 26, 2010

Most agree that the passage of the Patient Protection and Affordable Care Act will be a “game changer” in how physicians and their facilities will be reimbursed in the coming years.

One of its provisions requires a national pilot program for integrated payment during an inpatient episode of care. Herein, cardiologists and cardiothoracic surgeons will share in a “bundled” payment with their facilities for all services provided from three days prior to admission to 30 days post-discharge.

Bundled payments are based on MS-DRGs, a hospital reimbursement methodology implemented in October 2007. MS-DRGs are derived from ICD-9-CM codes based on explicit physician documentation. (Coders may not assume what the physician meant.)

Certain diagnoses and procedures require more resources and are thus assigned higher relative weights. Unless the physician defines and documents these conditions and procedures, fewer resources are available to address the work performed by all parties.

MS-DRGs are determined as follows:

Principal diagnosis: Defined as the documented condition found after study to have occasioned the inpatient admission. For example, in percutanueous transluminal coronary angioplasties and coronary artery bypass grafts, this may be coronary atherosclerosis or an acute myocardial infarction (MI). Note that coders may not report uncertain diagnoses (e.g., chest pain probably due to gastroesophageal reflux disease or syncope likely due to ventricular tachycardia) unless physicians document them at the time of discharge.

Procedures: Coders read the entire operative or cardiac catheterization report to code procedures, so physicians must be explicit about what they do and how they do it. For example, ICD-9-CM requires coding of any documented right atrial or coronary sinus angiography performed during cardiac resynchronization pacemaker implantation, even if the physician believes these are integral to the procedure. MS-DRGs have different relative weights for implantation of drug-eluting and non-drug-eluting stents, so the physician must document which one he or she uses.

Secondary diagnoses: MS-DRGs increase relative weight when physicians define, diagnose, and document significant comorbidities using official ICD-9-CM terminology. These complications and comorbidities (CC) and major CCs (MCC) increase the relative weight by an average of 0.25 to 0.5 in medicine cases and 0.7 to 1.3 in surgical cases.

Heart failure (HF): MS-DRGs do not recognize congestive HF (CHF), decompensated CHF, or systolic/diastolic dysfunction as CCs or MCCs. On the other hand, systolic (or diastolic) HF is a CC, and acute systolic (or diastolic) HF is an MCC. Because no code exists for HF with preserved systolic function, the physician must document diastolic HF to qualify.

ICD-9-CM does not allow coders to assume systolic or diastolic HF along with cardiogenic shock or cardiac tamponade unless the physician provides documentation.

Acute coronary syndrome/non-ST segment elevation MI: In 2007, a global cardiology task force defined myocardial infarction as cardiac myonecrosis due to ischemia, manifested by a rise or fall of the serum troponin with at least one value above the 99th percentile along with typical signs, symptoms, or electrocardiogram findings.

Many hospital laboratories, however, do not publish what the 99th percentile value is, allowing for an outdated “intermediate” category along with “positive” and “negative.” Consequently, unstable angina patients with elevated troponin levels may indeed qualify as acute MI if the 99th percentile was identified.

Positive troponins: A January perspective article in Clinical Chemistry reports that 0.7% of the population has chronically elevated troponins above the 99th percentile. Furthermore, troponin levels rise in non-ischemic cardiac diseases, such as acute pericarditis, myocarditis, and Takosubo syndrome. An elevated troponin in acute (systolic or diastolic) HF is associated with higher mortality. Unfortunately, non-ischemic cardiac myonecrosis codes to MI, even when no coronary vascular pathology is present. Physicians should discuss this with their coding staff so they can accurately represent the clinical significance of elevated troponins.

Indications for vasopressors and inotropes: If physicians use dopamine, norepinephrine, dobutamine, norephinephrine, milronone, or similar agents, they should indicate when hypotension or cardiogenic shock is present.

Indications for antiarrythmics: If a patient requires amiodarone, propafenone, or another antiarrhythmic, physicians should indicate the rhythm being suppressed (e.g., atrial fibrillation or flutter, ventricular tachycardia).

Hypertensive crisis: Believe it or not, hypertensive crisis, urgency, and emergency receive the same codes as well-controlled hypertension unless the physician specifies when acute end-organ damage occurs or whether there is hypertensive neuroretinopathy to support a documented diagnosis of accelerated or malignant hypertension.

Cardiorenal syndrome: A pathophysiologic disorder of the heart and kidneys whereby acute or chronic dysfunction of one organ may induce acute or chronic dysfunction of the other, cardiorenal syndrome may suggest acute kidney injury or chronic kidney disease and its staging (not chronic renal insufficiency), which physicians must document separately to be coded.

Pulmonary edema: Not all pulmonary edema is cardiogenic in origin (e.g., fluid overload from dialysis noncompliance). Physicians need to indicate when pulmonary is noncardiogenic or, in the setting of known CHF, the extent it is due to CHF.

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